Sealing structure of soft sealing ball valve

Abstract

The utility model discloses a sealing structure of a soft sealing ball valve, which relates to the field of ball valve sealing structures and comprises a valve body, a side body and a ball body. A gasket is arranged between the valve body and the side body, and the cross section of the gasket is octagonal; a first trapezoidal groove is formed in the valve body, a second trapezoidal groove is formed in the side body, and the gasket is arranged between the first trapezoidal groove and the second trapezoidal groove; a valve seat is arranged between the ball body and the valve body and between the ball body and the side body, a near-ball-side chamfer is arranged on one side, facing the ball body, of the valve seat, the edge of the near-ball-side chamfer is in close contact with the ball body, and a far-ball-side chamfer is arranged on one side, back to the ball body, of the valve seat. By means of the gasket with the octagonal cross section, good sealing performance can still be kept under the condition of temperature change, and meanwhile, due to the chamfer design of the valve seat, the problem that the valve seat shrinks when cooled, the torque of the valve is increased, and opening and closing are difficult is solved.

Description

Technical Field

[0001] This utility model relates to the field of ball valve sealing structures, and more particularly to a sealing structure for a soft-seal ball valve. Background Technology

[0002] Existing soft-seal floating ball valves are widely used in various industries due to their simple and compact structure, reliable sealing, convenient maintenance, and rapid opening and closing. The valve seat and gasket of these valves are commonly made of polytetrafluoroethylene (PTFE). PTFE exhibits stable performance under stable temperatures and does not cause problems. However, conventional gaskets are rectangular in shape. When the valve fluctuates between low and high temperatures, PTFE is sensitive to temperature changes. Due to thermal expansion and contraction, the volume of the gasket also shrinks or expands, leading to a gradual decrease in the sealing force and ultimately leakage.

[0003] In addition, due to temperature changes, the valve seat size will also change due to thermal expansion and contraction. Ordinary valve seats and balls are in surface contact. For example, in winter when the temperature is low, the inner diameter of the side of the valve seat that mates with the ball will become smaller. When the inner diameter of the valve seat shrinks, the wedge-shaped effect of the valve seat sealing part increases the wedge force between the valve seat and the ball, which will significantly increase the valve torque. In severe cases, the valve will be difficult to open and close. Utility Model Content

[0004] The purpose of this invention is to provide a sealing structure for a soft-seal ball valve, which solves the problem mentioned in the background art that conventional rectangular gaskets are easily deformed by thermal expansion and contraction when the temperature fluctuates between low and high temperatures, resulting in a decrease in the sealing force.

[0005] The present invention adopts the following technical solution:

[0006] This utility model discloses a sealing structure for a soft-seal ball valve, comprising a valve body, a side body, and a ball. The valve body and the side body are fastened together by a bolt assembly. The ball is rotatably and sealingly disposed between the valve body and the side body. A gasket is disposed between the valve body and the side body, and the gasket has an octagonal cross-section.

[0007] A first trapezoidal groove is provided on the contact surface between the valve body and the side body, and a second trapezoidal groove is provided on the contact surface between the side body and the valve body. The side wall of the gasket is in close contact with the side walls of the first trapezoidal groove and the second trapezoidal groove.

[0008] Preferably, the angle between the inner and outer inclined edges of the gasket and the vertical reference plane is the first reference tilt angle, and the range of the first reference tilt angle is 30 degrees to 50 degrees.

[0009] The inner inclination angles of the first trapezoidal groove and the second trapezoidal groove are matched with the first reference inclination angle of the gasket.

[0010] Preferably, a valve seat is provided between the ball and the valve body, and between the ball and the side body. The valve seat has a near-ball chamfer on the side facing the ball, and the edge of the near-ball chamfer near the center of the valve seat is in close contact with the ball. The valve seat has a far-ball chamfer on the side away from the ball.

[0011] Preferably, the valve body and the side body are provided with valve seat mounting grooves, and the valve seat is disposed in the valve seat mounting grooves.

[0012] Preferably, the valve seat includes an inner edge, an outer edge, a near-spherical edge, and a far-spherical edge;

[0013] The near-spherical chamfer extends from the inner edge to the edge of the near-sphere.

[0014] The chamfer on the far sphere side extends from the inner edge to the edge of the far sphere.

[0015] Preferably, the near-spherical chamfer is triangular in shape, and the angle range of the near-spherical chamfer is 130 degrees to 150 degrees.

[0016] Preferably, the valve seat is provided with a vertical slit and an arc-shaped slit. The vertical slit extends vertically downward from the inner edge away from the sphere and connects with one end of the arc-shaped slit. The other end of the arc-shaped slit extends to the edge of the far sphere.

[0017] The vertical tangent and the arc-shaped tangent together form the far spherical chamfer.

[0018] Preferably, a chamfered edge is provided at the intersection of the outer edge and the far sphere edge, and the angle between the chamfered edge and the outer edge is 45 degrees to 70 degrees.

[0019] Compared with the prior art, the beneficial technical effects of this utility model are as follows:

[0020] This invention features an octagonal gasket that maintains excellent sealing performance regardless of temperature changes. Furthermore, the valve seat incorporates chamfers on both the near and far sides to prevent increased valve torque due to seat contraction during cooling, which could lead to opening and closing difficulties. This invention requires only modifications to the machined surfaces of the valve body and sides, and the addition of a special elastic structure to the valve seat, while keeping other components unchanged. This design results in relatively low costs, facilitating production management and cost savings. Attached Figure Description

[0021] The present invention will be further described below with reference to the accompanying drawings.

[0022] Figure 1 This is a schematic diagram of the sealing structure of the soft-seal ball valve of this utility model;

[0023] Figure 2 This is a schematic diagram of the gasket structure in the sealing structure of the soft-seal ball valve of this utility model;

[0024] Figure 3 This is a schematic diagram of the valve seat structure in the sealing structure of the soft-seal ball valve of this utility model. Figure 1 ;

[0025] Figure 4 This is a schematic diagram of the valve seat structure in the sealing structure of the soft-seal ball valve of this utility model. Figure 2 ;

[0026] Figure 5 This is a schematic diagram showing the deformation of the gasket in the sealing structure of the soft-seal ball valve of this utility model;

[0027] Figure 6 This is a schematic diagram of the valve seat deformation in the sealing structure of the soft-seal ball valve of this utility model.

[0028] Explanation of reference numerals in the attached drawings: 1. Valve body; 1-1. First trapezoidal groove; 2. Side body; 2-1. Second trapezoidal groove; 3. Ball; 4. Valve stem; 5. Gasket; 5-1. First reference tilt angle; 6. Valve seat; 6-1. Chamfer on the near-ball side; 6-2. Chamfer on the far-ball side; 6-3. Inner edge; 6-4. Outer edge; 6-5. Near-ball edge; 6-6. Far-ball edge; 6-7. Vertical tangent edge; 6-8. Arc-shaped tangent edge; 6-9. Chamfered edge; 7. Valve seat mounting groove. Detailed Implementation

[0029] To make the technical problems, technical solutions and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments.

[0030] like Figure 1 As shown, this embodiment discloses a sealing structure for a soft-seal ball valve, including a valve body 1, a side body 2, a ball 3, and a valve stem 4. The valve body 1 and the side body 2 are fastened together by a bolt assembly. The ball 3 is rotatably sealed between the valve body 1 and the side body 2. The upper end of the ball 3 is fixedly connected to the valve stem 4. The valve stem 4 is rotatably sealed on the upper part of the valve body 1.

[0031] like Figure 1 and Figure 2As shown, a gasket 5 is provided between the valve body 1 and the side body 2, and the gasket 5 has an octagonal cross-section. A first trapezoidal groove 1-1 is provided on the contact surface between the valve body 1 and the side body 2, and a second trapezoidal groove 2-1 is provided on the contact surface between the side body 2 and the valve body 1. The gasket 5 is positioned between the first trapezoidal groove 1-1 and the second trapezoidal groove 2-1, and the sidewall of the gasket 5 is in close contact with the sidewall of the first trapezoidal groove 1-1 and the second trapezoidal groove 2-1. The angle between the inner and outer inclined sides of the gasket 5 and the vertical reference plane is the first reference inclination angle 5-1, which ranges from 30 degrees to 50 degrees. The inner inclination angles of the first trapezoidal groove 1-1 and the second trapezoidal groove 2-1 match the first reference inclination angle 5-1 of the gasket 5.

[0032] When the temperature decreases, the gasket 5 shrinks towards the center due to the cold. The two sides of the octagonal cross-section of the gasket 5 near the center are squeezed into the inner inclined edges of the first trapezoidal groove 1-1 and the second trapezoidal groove 2-1, ensuring a seal. When the temperature increases, the gasket 5 expands outwards due to the heat. The two sides of the octagonal cross-section of the gasket 5 away from the center are squeezed into the outer inclined edges of the first trapezoidal groove 1-1 and the second trapezoidal groove 2-1, still ensuring a seal.

[0033] like Figure 1 , Figure 3 and Figure 4 As shown, a valve seat 6 is provided between the ball 3 and the valve body 1, and between the ball 3 and the side body 2. The valve seat 6 has a near-ball chamfer 6-1 on the side facing the ball 3. The edge of the near-ball chamfer 6-1, close to the center of the valve seat 6, is in close contact with the ball 3. The valve seat 6 has a far-ball chamfer 6-2 on the side facing away from the ball 3. The design of the far-ball chamfer 6-2 helps the upper part of the valve seat 6 deform outwards when squeezed by the ball 3 during contraction. Thanks to the design of the near-ball chamfer 6-1, its edge is in contact with the ball 3. Even when the temperature decreases and the valve seat 6 contracts towards its center, the edge of the near-ball chamfer 6-1 near the center of the valve seat 6 is blocked by the ball 3, causing the near-ball chamfer 6-1 to deform. The corresponding far-ball chamfer 6-2 on the outer side is squeezed and reduced. At this time, the contact area between the valve seat 6 and the ball 3 does not increase significantly, thus not affecting the valve's friction torque.

[0034] In this embodiment, valve body 1 and side body 2 are provided with valve seat mounting grooves 7, and valve seat 6 is tightly installed in valve seat mounting grooves 7.

[0035] In this embodiment, the valve seat 6 includes an inner edge 6-3, an outer edge 6-4, a near-spherical edge 6-5, and a far-spherical edge 6-6. The near-spherical chamfer 6-1 extends from the inner edge 6-3 to the near-spherical edge 6-5, and the far-spherical chamfer 6-2 extends from the inner edge 6-3 to the far-spherical edge 6-6.

[0036] The near-spherical chamfer 6-1 is triangular in shape, and the angle range of the near-spherical chamfer 6-1 is 130 degrees to 150 degrees.

[0037] The valve seat 6 is provided with a vertical tangent 6-7 and an arc-shaped tangent 6-8. The vertical tangent 6-7 extends vertically downward from the inner edge 6-3 away from the ball 3 and connects with one end of the arc-shaped tangent 6-8. The other end of the arc-shaped tangent 6-8 extends to the far spherical edge 6-6. The vertical tangent 6-7 and the arc-shaped tangent 6-8 together form a far spherical chamfer 6-2.

[0038] A chamfered edge 6-9 is provided at the intersection of the outer edge 6-4 and the far spherical edge 6-6, with the chamfered edge 6-9 forming an angle of 45 degrees to 70 degrees with the outer edge 6-4. The chamfered edge 6-9 design helps the bottom surface of the valve seat 6 to be properly assembled and increases the bottom sealing pressure. Under normal operating conditions after installation, the near spherical edge 6-5, the outer edge 6-4, and the far spherical edge 6-6 are in close contact with the inner wall of the valve seat mounting groove 7.

[0039] like Figure 5 The diagram shown illustrates the deformation of gasket 5 under temperature influence. Figure 5 'a' represents the initial state (for ease of illustration, gaps are left between the gasket 5 and the first trapezoidal groove 1-1 and the second trapezoidal groove 2-1 in the diagram). When the temperature decreases... Figure 5 As shown in b, the gasket 5 shrinks when cooled, that is, it shrinks towards the center of the whole circle. At this time, the cross-section of the gasket 5 becomes smaller and converges towards the center of the gasket 5. The two sides of the octagonal cross-section of the gasket 5 near the center of the gasket 5 converge towards the inner inclined sides of the first trapezoidal groove 1-1 and the second trapezoidal groove 2-1 (i.e., Figure 5 (b) The upper two oblique edges are squeezed to form a seal. Due to the wedge effect, the sealing pressure increases, resulting in a good seal. If the temperature rises... Figure 5 As shown in Figure c, when the gasket 5 is heated, it expands outward from the circumference of the gasket 5. At this time, the two sides of the octagonal cross-section of the gasket 5 away from the center of the gasket 5 are inclined towards the outer sides of the first trapezoidal groove 1-1 and the second trapezoidal groove 2-1 (i.e., Figure 5 The lower two sloping sides of c are squeezed to form a seal, which can still maintain the airtightness.

[0040] like Figure 6The diagram shows the deformation of valve seat 6 when it contracts due to cold, with the dashed line representing its position after deformation. As the temperature decreases, valve seat 6 contracts towards its center. The chamfer 6-1 near the ball is blocked by the ball 3 and begins to deform, expanding. The corresponding chamfer 6-2 on the outer side is compressed and reduced, meaning the vertical tangent 6-7 bends and deforms towards the arc-shaped tangent 6-8. Due to the deformation of the chamfer 6-1 and the chamfer 6-2, the contact area between valve seat 6 and ball 3 does not significantly increase. Compared to conventional surface-contact valve seats, this reduces the wedging force of valve seat 6. Because the stress on valve seat 6 is reduced, cold flow is avoided. Simultaneously, the frictional torque between valve seat 6 and ball 3 does not increase significantly, ensuring normal valve opening and sealing.

[0041] The embodiments described above are merely preferred embodiments of the present utility model and are not intended to limit the scope of the present utility model. Various modifications and improvements made to the technical solutions of the present utility model by those skilled in the art without departing from the spirit of the present utility model should fall within the protection scope defined by the claims of the present utility model.

Claims

1. A sealing structure for a soft-seal ball valve, comprising a valve body (1), a side body (2), and a ball (3), wherein the valve body (1) and the side body (2) are fastened together by a bolt assembly, and the ball (3) is rotatably disposed between the valve body (1) and the side body (2), characterized in that: A gasket (5) is provided between the valve body (1) and the side body (2), and the cross-section of the gasket (5) is octagonal; A first trapezoidal groove (1-1) is provided on the contact surface between the valve body (1) and the side body (2), and a second trapezoidal groove (2-1) is provided on the contact surface between the side body (2) and the valve body (1). The side wall of the gasket (5) is in close contact with the side walls of the first trapezoidal groove (1-1) and the second trapezoidal groove (2-1).

2. The sealing structure of the soft-seal ball valve according to claim 1, characterized in that: The angle between the inner and outer inclined sides of the gasket (5) and the vertical reference plane is the first reference tilt angle (5-1), and the range of the first reference tilt angle (5-1) is 30 degrees to 50 degrees. The inner inclination angles of the first trapezoidal groove (1-1) and the second trapezoidal groove (2-1) are matched with the first reference inclination angle (5-1) of the gasket (5).

3. The sealing structure of the soft-seal ball valve according to claim 1, characterized in that: A valve seat (6) is provided between the ball (3) and the valve body (1) and between the ball (3) and the side body (2). The valve seat (6) has a near-ball chamfer (6-1) on the side facing the ball (3). The edge of the near-ball chamfer (6-1) near the center of the valve seat (6) is in close contact with the ball (3). The valve seat (6) has a far-ball chamfer (6-2) on the side away from the ball (3).

4. The sealing structure of the soft-seal ball valve according to claim 3, characterized in that: The valve body (1) and the side body (2) are provided with valve seat mounting grooves (7), and the valve seat (6) is disposed in the valve seat mounting grooves (7).

5. The sealing structure of the soft-seal ball valve according to claim 3, characterized in that: The valve seat (6) includes an inner edge (6-3), an outer edge (6-4), a near-spherical edge (6-5), and a far-spherical edge (6-6). The near-spherical chamfer (6-1) extends from the inner edge (6-3) to the near-spherical edge (6-5). The chamfer (6-2) on the far sphere side extends from the inner edge (6-3) to the edge (6-6) of the far sphere.

6. The sealing structure of the soft-seal ball valve according to claim 5, characterized in that: The near-spherical chamfer (6-1) is triangular in shape, and the angle range of the near-spherical chamfer (6-1) is 130 degrees to 150 degrees.

7. The sealing structure of the soft-seal ball valve according to claim 5, characterized in that: The valve seat (6) is provided with a vertical cut edge (6-7) and an arc cut edge (6-8). The vertical cut edge (6-7) extends vertically downward from the inner edge (6-3) away from the sphere (3) and connects with one end of the arc cut edge (6-8). The other end of the arc cut edge (6-8) extends to the far sphere edge (6-6). The vertical tangent (6-7) and the arc-shaped tangent (6-8) together form the far spherical chamfer (6-2).

8. The sealing structure of the soft-seal ball valve according to claim 5, characterized in that: A chamfered edge (6-9) is provided at the intersection of the outer edge (6-4) and the far spherical edge (6-6), and the angle between the chamfered edge (6-9) and the outer edge (6-4) is 45 degrees to 70 degrees.

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